Edward Jenner
learned early in his medical career of the farm worker's' belief that if at one time one
had cowpox, one would not get smallpox. Cowpox caused mild discomfort, aching, a few
pustules, some swelling, symptoms that disappeared in a few days. In contrast, smallpox
was a scourge. It infected whole population centers throughout the world. The
pustules of the disease caused massive disfigurement, in its worse case blindness, and in
many cases killed its victims. Populations of towns and villages could be decimated. As
recently as 1967, ten years before the successful efforts of the World Health Organization
to eradicate smallpox by isolation and vaccination, two millions persons died of this
disease. Prior to the discovery of vaccination by Jenner,
protection against a severe or fatal case of smallpox was generally achieved by giving
subjects a mild (it was hoped) case of smallpox by inoculation of the smallpox virus. This
approach, termed variolation, was difficult to control as the severity of
the induced disease was hard to predict. Worse, such subjects, even if not debilitated by
the inoculation, became carriers of the disease and contributed to its further spread in
the community. Working by himself with his own financial resources,
Jenner, a successful practicing physician, collated cases of subjects who had suffered
from cowpox and were subsequently immune to smallpox. His thesis "that the Cow-pox
protects the human constitution from the infection of the Small-pox" was tested by
vaccinating patients with fluid from pustles of cowpox-infected patients and then showing
that these subjects were immune to smallpox. Equally important, he showed that the cowpox
vaccine "in passing from one human subject to another (arm-to-arm transfer)... lost
none of its protective properties". This was a critical observation as it made it
possible to obtain a continual supply of vaccine - this because cowpox infection in cows
was sporadic and rare. Jenner wrote up his study and in 1797 submitted it for
publication in the Philosophical Transactions of the Royal Society which
found the work preliminary and returned the paper with no comment. Jenner added additional
cases and paid a printer to publish Inquiry. Two addenda entitled Further
Observations followed in 1798 and 1799. A third addenda, Origin of the Vaccine
Innoculation followed in 1801 (see below).Inquiry wasa landmark contribution to the science
of medicine and biology. It established the foundations of preventive medicine and
immunology, and was the precursor of the work on immunity against anthrax and rabies by
Pasteur and on tuberculosis by Koch more than three-quarters of a century later. In 1881,
following the wildly successful and highly publicized protection of sheep with attenuated
anthrax virus at Pouilly-le-Forte , Pasteur adapted the terms vaccine and vaccination
for his research "to the honor and immense services rendered one of the greatest
Englishmen, ...Jenner". A facsimile version of Inquiry is offered here. You
will need Acrobat Reader for access. (You may download the Reader at no charge from the
Adobe site by clicking here). In order to decrease download time, the
text is divided into Parts A, B and C. Viewing will be best at "actual
size". (See Notes &
Definitions page for exposition on the term virus as used by Jenner)

Three years after publication of
"Inquiry", the practice of smallpox vaccination had begun to spread throughout
the world. Jenner reported that by 1801 over 100,000 persons in England had been
vaccinated. Vaccination had been introduced into many countries including several British
possessions, France, Spain, the United States and Canada. Despite these successes, all was not smooth sailing for
vaccination. There were many who doubted the unique ability of cowpox to prevent smallpox
and opposed its practice, suggesting, rather, that the treatment was no more than a
variation of variolation. This idea was fortified by events occurring in the
Smallpox and Inoculation Hospitals in London, an institution initially dedicated to
variolation, that now began to practice vaccination under the direction of Drs. Woodville
and Pearson. Patients treated with cowpox vaccines would develop numerous pustules, more
like smallpox sores, and quite unlike the single inoculation pustule that Jenner reported.
Such pustules, we now believe, were due to contamination of the vaccines with smallpox
virus that infested the smallpox institution. A brisk debate between Woodville on one side
and Jenner on the other caused some in the medical profession to question Jenner's
discovery. Contributing to this questioning of the effectiveness of
vaccination was the apparent use by some practitioners of exudates from unrelated
infections of a cow's udder that they assumed were cowpox (called by Jenner Spurious
Cowpox). Operators using such exudates would report failureto protect against smallpox
which they then attributed to failure of cowpox itself. Even when the source of the
vaccine was from true cowpox exudates, some reported failures could be attributed to
degradation of the vaccine through improper storage and bacterial decomposition. Finally there were occasional reports of individuals who
had earlier been infected with cowpox who years later developed smallpox, reports directly
contradictory to Jenner's hypothesis of permanent immunity. Not known at that time by
Jenner or his supporters is that vaccination against smallpox is not permanent but must be
reinforced every 5 to 10 years. In addition, because of the existence of spurious cowpox,
some who believed that they had been infected by cowpox might not have been. In an effort to clarify several of these issues, Jenner
published in 1801 the fourth of this pamphlets on smallpox vaccination: "The Origin
of the Vaccine Inoculation". This pamphlet is reproduced here. The copy was scanned
from a facsimile copy of the Second Issue, London (coded No. 55 by W. R. LeFanu). (Click Here for PDF file).